[PATCH] qede: fix crash in rmmod qede while automatic debug collection

[PATCH] qede: fix crash in rmmod qede while automatic debug collection

[Prabhakar Kushwaha]

A crash has been observed if rmmod is done while automatic debug
collection in progress. It is due to a race  condition between
both of them.

To fix stop the sp_task during unload to avoid running qede_sp_task
even if they are schedule during removal process.

Signed-off-by: Alok Prasad <palok@marvell.com>
Signed-off-by: Shai Malin <smalin@marvell.com>
Signed-off-by: Ariel Elior <aelior@marvell.com>
Signed-off-by: Prabhakar Kushwaha <pkushwaha@marvell.com>
---
 drivers/net/ethernet/qlogic/qede/qede.h      | 1 +
 drivers/net/ethernet/qlogic/qede/qede_main.c | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/drivers/net/ethernet/qlogic/qede/qede.h b/drivers/net/ethernet/qlogic/qede/qede.h
index 2e62a2c4eb63..5630008f38b7 100644
--- a/drivers/net/ethernet/qlogic/qede/qede.h
+++ b/drivers/net/ethernet/qlogic/qede/qede.h
@@ -501,6 +501,7 @@ struct qede_fastpath {
 #define QEDE_SP_HW_ERR                  4
 #define QEDE_SP_ARFS_CONFIG             5
 #define QEDE_SP_AER			7
+#define QEDE_SP_DISABLE			8
 
 #ifdef CONFIG_RFS_ACCEL
 int qede_rx_flow_steer(struct net_device *dev, const struct sk_buff *skb,
diff --git a/drivers/net/ethernet/qlogic/qede/qede_main.c b/drivers/net/ethernet/qlogic/qede/qede_main.c
index 173878696143..6a4bc7652d2e 100644
--- a/drivers/net/ethernet/qlogic/qede/qede_main.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_main.c
@@ -1009,6 +1009,13 @@ static void qede_sp_task(struct work_struct *work)
 	struct qede_dev *edev = container_of(work, struct qede_dev,
 					     sp_task.work);
 
+	/* Disable execution of this deferred work once
+	 * qede removal is in progress, this stop any future
+	 * scheduling of sp_task.
+	 */
+	if (test_bit(QEDE_SP_DISABLE, &edev->sp_flags))
+		return;
+
 	/* The locking scheme depends on the specific flag:
 	 * In case of QEDE_SP_RECOVERY, acquiring the RTNL lock is required to
 	 * ensure that ongoing flows are ended and new ones are not started.
@@ -1300,6 +1307,7 @@ static void __qede_remove(struct pci_dev *pdev, enum qede_remove_mode mode)
 	qede_rdma_dev_remove(edev, (mode == QEDE_REMOVE_RECOVERY));
 
 	if (mode != QEDE_REMOVE_RECOVERY) {
+		set_bit(QEDE_SP_DISABLE, &edev->sp_flags);
 		unregister_netdev(ndev);
 
 		cancel_delayed_work_sync(&edev->sp_task);
-- 
2.24.1

Re: [PATCH] qede: fix crash in rmmod qede while automatic debug collection

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (refs/heads/master):

On Thu, 29 Jul 2021 14:43:06 +0300 you wrote:
> A crash has been observed if rmmod is done while automatic debug
> collection in progress. It is due to a race  condition between
> both of them.
> 
> To fix stop the sp_task during unload to avoid running qede_sp_task
> even if they are schedule during removal process.
> 
> [...]

Here is the summary with links:
  - qede: fix crash in rmmod qede while automatic debug collection
    https://git.kernel.org/netdev/net/c/1159e25c1374

You are awesome, thank you!
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